A research team headed by materials scientist Anirudha Sumant from Argonne National Laboratory's (ANL) Center for Nanoscale Materials has carved nanowires from thin films of ultra-nanocrystalline diamond (UNCD), enhancing the functionality of the material and offering considerable improvements in biosensor fabrication.

The research findings will be presented at the AVS' 58th International Symposium & Exhibition to be held from 30 October to 4 November, 2011 in Nashville, Tenn.

ANL researchers have discovered UNCD thin films, which are an exclusive type of diamond that has the capability to modify its electrical characteristics when the chemical bonding is altered between grain boundaries. Sumant stated that this carbon-based film can be used in a variety of applications such as in defense, medicine and communications.

According to him, a main objective of the research was to study UNCD’s electrical transport characteristics when it is formed into a nanowire. The researchers also desired to understand how these characteristics can be modified by altering chemical bonding at the grain boundary and by using the enhanced surface-to-volume ratio simultaneously.

Sumant added that they have shown the technique to form UNCD nanowires with narrow widths of 30 nm at 40 nm thickness by using a top-down fabrication method, which uses both reactive ion etching and electron beam lithography.

The UNCD nanowires have unique electrical characteristics, which includes a resistance that is highly sensitive to gas molecule adsorption at the grain boundary. This will enable fabricating sophisticated nanoscale sensors for particular applications.

One of the key benefit of UNCD is a stable functionalization that will enable the fabrication of a novel sensor range. UNCD nanowires will find usage in gas, pressure sensors or biosensors that can be used in the semiconductor and MEMS industries.